Gearbox classification

The gearbox has the following functions:
1, to expand the drive wheel torque and speed range to adapt to the changing conditions of travel, while the engine in the favorable (high power and low fuel consumption) under the conditions of work;
2, in the direction of the engine rotation unchanged, the car can go backwards;
3, the use of neutral, interrupt power transmission to the engine to start, idle, and easy to shift gear or power output.
According to the transmission ratio to change the way points:
The stepless transmission is currently the most widely used. It uses a gear drive, with a number of fixed transmission ratio. According to the type of wheel used, there are two kinds of fixed-type fixed transmission (ordinary transmission) and rotary rotary transmission (planetary gear transmission). At present, cars and light and medium-sized truck transmission transmission ratio is usually 3-5 forward and a reverse gear, heavy trucks in the modular transmission, there are more stalls. The so-called transmission file number refers to the forward gear number.
Continuously variable transmission of its transmission ratio in a certain range of values ​​can be infinitely many levels of change, common with electric and hydraulic (moving liquid) two. The variable speed drive part of the electric type continuously variable transmission is a DC series choke motor, and it is widely used in the super heavy duty dump truck transmission system. The transmission parts of the moving fluid type continuously variable transmission are hydraulic torque converter.
By way of manipulation:
Forcedly operated transmission: the shift lever is directly operated by the driver.
Automatic transmission of the transmission: the transmission ratio selection and the shift is automatically carried out, the so-called "automatic" refers to the mechanical transmission of each gear is to reflect the engine load and speed of the signal system to control the shift system implementation of the components And realized. The driver only needs to manipulate the accelerator pedal to control the speed.
There are two types of semi-automatic transmission: one is commonly used in several stalls automatically manipulated, the rest of the stalls by the driver; the other is pre-selected, that is, the driver with the button to select the stalls, When the clutch pedal is released or the accelerator pedal is released, an electromagnetic device or hydraulic device is switched on for gearshift.